Study Achieves 52 Percent Dose Reduction in Cardiac CT

June 10, 2009 - A study conducted by the Michigan Advanced Cardiovascular Imaging Consortium monitored radiation doses of patients receiving coronary artery CT scans over a year, and by providing oversight and instructing participating hospitals in best practices, researchers were able to reduce the median dose of radiation from a cardiac CT scan from 25 to 12 millisieverts (mSv), a 52 percent reduction.

After reviewing the median radiation doses of 15 participating hospitals in Michigan, Gilbert Raff, M.D., director of the Ministrelli Center for Advanced Cardiovascular Imaging at William Beaumont Hospital in Royal Oak, Mich., saw a need for improvement. By implementing physician oversight in the administration of CT scans, Dr. Raff believed the radiation dosage could be greatly decreased.

The study is published in the June 10, 2009, issue of the Journal of the American Medical Association (Vol. 301:22, pp. 2,340-2,348).

Assembling a team that included a lead CT technologist and a radiation physicist, Dr. Raff identified best practices for lowering radiation doses, including ECG X-ray tube current modulation and reduced tube voltage in normal weight patients. These recommendations were then presented to participating hospitals and their use, as well as the quality of the images being obtained, was carefully monitored. Applying those practices and techniques, researchers saw a continuous decline in radiation dose over the course of the study without any negative impact on image quality.

“Cardiac CT has a lot of technical tricks for lowering radiation dosage, unlike many other exams where you just push the button,” said Dr. Raff. “The methods we used have been around for a couple years and have the ability to lower radiation to as little as 5 mSv, depending on the patient as some patients require higher doses for technical reasons. My hope is that physicians and radiologists who are not already using these techniques will utilize them in their practices in order to lower the radiation risk associated with CCT to improve the quality of patient care.”

Dr. Raff is chair of the Society of Cardiovascular Computed Tomography’s Guidelines Committee, which is working to publish definitive image acquisition guidelines for cardiac CT, of which radiation dose is an integral part. The findings of the study were presented as an abstract at the American Heart Association Meeting last November under the title “Marked Radiation Dose Reduction in a Statewide Coronary CT Quality Improvement Registry.”

The Society of Cardiovascular Computed Tomography (SCCT) is the recognized representative and advocate for physicians, scientists, and technologists who work in the field of cardiovascular computed tomography. With nearly 4,000 members, SCCT is nationally and internationally viewed as the principal organization committed to the further development of cardiovascular computed tomography through research, education, quality and advocacy.